For safety reasons, vehicle seats include a headrest, which in the event of an accident serves as protection for preventing rearward movement of the head.
In order to be able to fulfill their safety function, it must be possible for headrests to be height-adjustable so that they can be adapted to the height of the seat user, and said adjustment must be simple and secure.
Currently, to allow such adjustment, headrests comprise a pair of fixing rods housed inside the seat back, in particular inside guide elements placed in the seat back.
These guide elements comprise a retaining element that can be moved between a retaining position, in which the retaining element is housed in a notch made in the fixing rod, preventing the movement of the fixing rod with respect to the guide element, to a release position in which the fixing rod can move with respect to the guide element in order to adjust the height of the headrest.
This adjustment is achieved by actuating a push button, which allows said retaining element to be moved from its retaining position to its release position.
In the majority of guides, the retainer is located at the same level as the actuation mechanism outside the seat structure. In other cases, the retainer is located inside the seat structure, such that it is necessary to incorporate, aside from the retaining and actuation elements, a mechanism capable of transmitting movement between the parts, thereby increasing the number of required components, and the costs of assembly and manufacture.